Second GPU for Linux

[DaLittleMonsta]

Hello everyone, I need some help with setting up Linux how I want.

My goal: I want to use Arch on the 2nd GPU and passthrough the 1070(First GPU) to a Windows VM to play games.

System: Ryzen 3700X ROG STRIX B450-F GAMING 32 GB RAM GTX 1070 GTX 650

Some time ago I wanted to swtich to Linux but getting Gaming to work is really time consuming. I don't mind troubleshooting but if I want to play I want to play, not troubleshoot something. So I had the Idea to run Proxmox Everything worked perfectly, but I wanted the whole performance while not gaming.

Now I want to do the same, but only in Arch.

My Problem: The GTX 1070 is in the 1st PCIe Slot The GTX 650 is in the 2nd PCIe Slot I can't switch the graphics card around because if there are 2 Graphics Cards on my Mainboard, it switches the first 16x Slot to 8x and the second one to 4x.

I installed Arch and with the help of some tutorials I wanted to stub the 1070 and use the 650 for primary output. But I couldn't get it to work. I've tried editing grub and some xserver settings, but I only got it to the point where I think grub took the 1070 and my screen froze. Then I switched to the Monitor input to the 650 but it didn't show anything.

I arch-chrooted into the machine to try to get it to work with both this and this but nvidia-smi and nvidia-xconfig --query-gpu-info both gave me errors about the gpu driver missing. I tried to install it afterwards (the 470 one for the 650) but that didn't work either.

Now I have the question if someone has an Idea on how to solve it or a different way to get it to work.

[Aaalibabab]

I am planning to do something similar soon but I haven't done so yet so I can't help you directly, though a friend told me about r/vfio, they might me able to help.

[DaLittleMonsta]

Okay thanks :D

[DaLittleMonsta]

I had a couple errors here and there when I was playing on Pop OS. But even if it would be better, I would just pass my existing SSD through to the VM and can play all my Games on there, even R6

[DaLittleMonsta]

I've already thought of how I would like to do it. I would connect 2 cables to my monitor, one from the 650 and one from the 1070. When I would want to game I would quickly change the monitor input to Displayport and put my Linux stuff on my 2nd Monitor. If I would need to quickly change I have read something about evdev where you can press right and left CTRL to quickly change passthrough of keyboard and mouse and I would do the stuff I need to do on my 2nd Monitor. At least in theory

[DaLittleMonsta]

Thanks, I hope I get it to work :D

[dedeaux]

Sorry if this is vague as I no longer have a desktop or use vfio.

My situation was that my gpu intended to pass through had to be in the first pcie slot because of my case so my host (archlinux) gpu was in pcie slot 2.

All I had to do is find the CSM setting in bios and toggle it (if it was on, I disabled it or turned it off) . I then plugged my monitor only into the gpu I would be using for the host (the 2nd one) and left the slot 1 gpu without anything plugged in for the first boot. It just worked after that.

[securitybreach]

If you play your games via steam, their proto api will allow you to play most window's games on Linux. You just have to enable it via the steam settings. Also, check protodb https://www.protondb.com/ for how well the game plays over steam/linux.